Secondary battery

Abstract

A secondary battery includes an electrode assembly including a negative electrode plate including a negative electrode leading end uncoated portion, a positive electrode plate including a positive electrode leading end uncoated portion, and an anti-deformation portion attached to the positive electrode leading end uncoated portion, an end of the positive electrode leading end uncoated portion and an end of the anti-deformation portion being located ahead of an end of the negative electrode leading end uncoated portion, a case accommodating the electrode assembly, and electrically coupled to the negative electrode plate, and a cap assembly sealing the case.

What is claimed is: 
     
         1 . A secondary battery comprising:
 an electrode assembly comprising:
 a negative electrode plate comprising a negative electrode leading end uncoated portion; 
 a positive electrode plate comprising a positive electrode leading end uncoated portion; and 
 an anti-deformation portion attached to the positive electrode leading end uncoated portion, an end of the positive electrode leading end uncoated portion and an end of the anti-deformation portion being located ahead of an end of the negative electrode leading end uncoated portion; 
   a case accommodating the electrode assembly, and electrically coupled to the negative electrode plate; and   a cap assembly sealing the case.   
     
     
         2 . The secondary battery as claimed in  claim 1 , wherein the end of the positive electrode leading end uncoated portion and the end of the anti-deformation portion are coplanar. 
     
     
         3 . The secondary battery as claimed in  claim 1 , wherein the positive electrode leading end uncoated portion comprises an extension portion extending from the end of the anti-deformation portion. 
     
     
         4 . The secondary battery as claimed in  claim 3 , further comprising at least three layers of separators between the extension portion and the negative electrode plate. 
     
     
         5 . The secondary battery as claimed in  claim 1 , wherein a length of the anti-deformation portion is about ⅓ to about ⅔ of a circumferential length of a core of the electrode assembly. 
     
     
         6 . The secondary battery as claimed in  claim 1 , wherein the anti-deformation portion is attached to a front surface and to a rear surface of the positive electrode leading end uncoated portion. 
     
     
         7 . The secondary battery as claimed in  claim 1 , wherein the positive electrode plate comprises at least two positive electrode tabs coupled between the positive electrode leading end uncoated portion and a positive electrode trailing end uncoated portion. 
     
     
         8 . The secondary battery as claimed in  claim 7 , wherein the cap assembly comprises:
 a cap plate electrically coupled to the case; and   a rivet terminal passing through, and insulated from, the cap plate, and electrically coupled to the at least two positive electrode tabs.   
     
     
         9 . The secondary battery as claimed in  claim 1 , wherein the negative electrode plate comprises at least one negative electrode tab coupled between the negative electrode leading end uncoated portion and a negative electrode trailing end uncoated portion. 
     
     
         10 . The secondary battery as claimed in  claim 9 , wherein the at least one negative electrode tab is electrically coupled to the case. 
     
     
         11 . The secondary battery as claimed in  claim 9 , wherein the negative electrode trailing end uncoated portion is directly coupled to the case. 
     
     
         12 . The secondary battery as claimed in  claim 1 , wherein the anti-deformation portion is outside the negative electrode leading end uncoated portion in a core of the electrode assembly. 
     
     
         13 . The secondary battery as claimed in  claim 1 , wherein the positive electrode plate comprises a positive electrode current collector comprising the positive electrode leading end uncoated portion, and a positive electrode active material on the positive electrode current collector and attached to the anti-deformation portion. 
     
     
         14 . The secondary battery as claimed in  claim 1 , wherein the negative electrode plate comprises a negative electrode current collector comprising the negative electrode leading end uncoated portion, and a negative electrode active material on the negative electrode current collector, and
 wherein the anti-deformation portion is outside the negative electrode active material.   
     
     
         15 . The secondary battery as claimed in  claim 7 , wherein the cap assembly comprises a cap-up coupled to the case, a safety vent coupled to the cap-up, and a cap-down coupled to the safety vent and electrically coupled to the at least two positive electrode tabs.